Professional Knowledge Quiz

Q.1 NULL is

(A) the same as 0 for integer
(B) the same as blank for character
(C) the same as 0 for integer and blank for character
(D) not a value


Q.2 Which of the following is record based logical model?
(A) Network Model
(B) Object oriented model
(C) E-R Model
(D) None of these

Q.3 A data dictionary is a special file that contains:
(A) The name of all fields in all files.
(B) The width of all fields in all files.
(C) The data type of all fields in all files.
(D) All of the above.

Q.4 A file manipulation command that extracts some of the records from a file is called
(A) SELECT
(B) PROJECT
(C) JOIN
(D) PRODUCT

Q.5 The physical location of a record is determined by a mathematical formula that transforms  a file key into a record location is :
(A) B-Tree File
(B) Hashed File
(C) Indexed File
(D) Sequential file.

Q.6 Using Relational Algebra the query that finds customers, who have a balance of over 1000 is
(A) PCustomer_name(s balance >1000(Deposit))
(B) s Customer_name(Pbalance >1000(Deposit))
(C) PCustomer_name(s balance >1000(Borrow))
(D) s Customer_name(Pbalance >1000(Borrow))

Q.7 A primary key is combined with a foreign key creates
(A) Parent-Child relation ship between the tables that connect them.
(B) Many to many relationship between the tables that connect them.
(C) Network model between the tables that connect them.
(D) None of the above.

Q.8 In E-R Diagram derived attribute are represented by
(A) Ellipse
(B) Dashed ellipse
(C) Rectangle
(D) Triangle

Q.9 Cross Product is a:
(A) U nary Operator
(B) Ternary Operator
(C) Binary Operator
(D) Not an operator

Q.10 An instance of relational schema R (A, B, C) has distinct values of A including NULL values. Which one of the following is true?
(A) A is a candidate key
(B) A is not a candidate key
(C) A is a primary Key
(D) Both (A) and (C)

Q.11 Consider the join of a relation R with relation S. If R has m tuples and S has n tuples, then the maximum size of join is:
(A) mn
(B) m+n
(C) (m+n)/2
(D) 2(m+n)

Q.12 The natural join is equal to :
(A) Cartesian Product
(B) Combination of Union and Cartesian product
(C) Combination of selection and Cartesian product
(D) Combination of projection and Cartesian product

Q.13 Which one of the following is not true for a view:
(A) View is derived from other tables.
(B) View is a virtual table.
(C) A view definition is permanently stored as part of the database.
(D) View never contains derived columns.

Q.14 A primary key if combined with a foreign key creates
(A) Parent-Child relationship between the tables that connect them.
(B) Many to many relationship between the tables that connect them.
(C) Network model between the tables that connect them.
(D) None of the above.

Q.15 In E-R Diagram relationship type is represented by
(A) Ellipse
(B) Dashed ellipse
(C) Rectangle
(D) Diamond


ANSWERS:
Ans 1: D
Ans 2: A
Ans 3: D
Ans 4: A
Ans 5: B
Ans 6: A
Ans 7: A
Ans 8: B
Ans 9: C
Ans 10: B
Ans 11: A
Ans 12: D
Ans 13: C
Ans 14: A
Ans 15: D